re:
The only reason to consider the Pixel is if having updates first is more important than anything else on the phone. If you need OS updates 3-4 months earlier than other devices just so you can feel special about yourself, get the Pixel. Or if you plan on keeping the phone for longer than two years and you want that extra year of support, then the Pixel will be a good buy.
Anything the Pixel does, with its stock version of Android, the V30 can also do. What the Pixel has over the V30 is supposedly a better a camera and front firing speakers. If having the best camera is more important than having a complete package with a good camera, then get the Pixel. Neither camera is bad and, coming from the V10, either is an update for you. Both will be good cameras.
If you're the kind of person who consistently listens to audio through your phone's speaker, then maybe the Pixel might be good for you. If wired/wireless headphones, BT speakers, casting your device, or just using another device with a larger screen to consume media at home doesn't work for you, maybe front firing speakers will.
The last reason to get a Pixel is if you're absolutely against OEM skins. Coming from the V10, I don't think you are. I'm a long time LG user and I've grown accustomed to their skin and it gets better with every new phone. Honestly, it's not that different from stock despite what people will have you believe. The most notable difference is the theme, which can be changed because LG includes that kind of feature with their skin, unlike boring stock Android that Google dishes out.
In person, the Pixel 2 XL looks kind of awkward to me. The larger bezels with the rounded screen corners just doesn't look right. It looks off, weird. The V30, on the other hand, looks great and feels great. Best in hand feel of any phone I've held. The only thing I like about the Pixel build over the V30 is that it weighs more. The V30 is very thin and very light. This, of course, is a personal preference.
Aside from that, the V30 is a more complete package. When it comes to the software, the Pixel isn't unique. The Pixel has Android, but completely stock. The V30 also has Android, but has more features baked in. It has a very useful wide angle camera. It has wireless charging. It just feels like a more complete package.